This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study proposes a genetic epidemiology approach using data, in part, collected by an ongoing, large, prospective cohort of kidney transplant recipients enrolled in a NIH-funded study (DeKAF). This study will determine how genetic predisposition may help to explain the outcomes defined in the DeKAF study. Specifically, this study will examine the link between genetic variants (SNPs), immune suppressant pharmacokinetics, adverse effects, and clinical outcomes. The overall objective is to test the relationship between specific genetic variants of drug metabolizing enzymes, drug transporters, drug targets and biological pathways associated with pharmacokinetics, adverse effects of immunosuppressants, and kidney rejection.